Originally Posted by séamuis 
it will also greatly depend on exposure.
No truer words have been written... wrong exposure can equal funky noise in any of the cameras...
I have got some very usable Iso 3200 shots with my K100d, but also a lot of noisy stinkers too. The K20 is definately an impovement in how the noise looks. A finer quality and less blotchy... but you still need to get the exposure right.